Physical configurations of a cell doublet with line tension, a theoretical study

As a first approximation, early embryos may be modeled as foams whose shape depends on the surface tensions of each cell. However it has been remarked that exist line tensions at polarized exterior cellular interfaces (apical). In order to understand the changes it may imply on the usual foam model, a simple case study is considered: a double cell with line tension. Phase diagrams, bifurcations, possible new configurations are studied

Compartmental analysis of dynamic nuclear medicine data: models and identifiability

Compartmental models based on tracer mass balance are extensively used in clinical and pre-clinical nuclear medicine in order to obtain quantitative information on tracer metabolism in the biological tissue. This paper is the first of a series of two that deal with the problem of tracer coefficient estimation via compartmental modelling in an inverse problem framework. Specifically, here we discuss the identifiability problem for a general n-dimension compartmental system and provide uniqueness results in the case of two-compartment and three-compartment compartmental models. The second paper will utilize this framework in order to show how non-linear regularization schemes can be applied to obtain numerical estimates of the tracer coefficients in the case of nuclear medicine data corresponding to brain, liver and kidney physiology

Identification de fissures par ondes acoustiques

Cette thèse porte sur le problème de reconstruction de fissures par ondes acoustiques. Le premier objectif consiste à développer une méthode d'inversion rapide utilisant un unique couple de données de Cauchy sur la frontière d'un domaine entourant la fissure sous l'hypothèse que la fissure cherchée est plane. L'utilisation de la fonctionnelle Écart à la Réciprocité nous fournit alors une méthode de reconstruction quasi explicite. Le second objectif consiste à trouver une méthode d'inversion pour le problème de Helmholtz en milieu inhomogène. L'utilisation de la fonctionnelle Écart à la Réciprocité combinée à une méthode de type "Sampling Method" permet alors la reconstruction de fissures de formes quelconques à partir de données en champ proche.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

On the use of the reciprocity-gap functional in inverse scattering from planar cracks

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